玄武岩-聚丙烯混杂纤维混凝土抗水渗透试验

Experiment of water permeation resistance of concrete with basalt-polypropylene hybrid fiber

采用渗水高度法对纤维掺加量为0.3%、0.6%、0.9%和1.2%的玄武岩纤维混凝土、聚丙烯纤维混凝土以及混杂比分别为1∶1、1∶2、2∶1的玄武岩-聚丙烯混杂纤维混凝土进行28d龄期的抗水渗透性能试验.得到各系列混凝土的渗水高度变化规律.结果表明:玄武岩纤维系列对混凝土基体抗渗性有较小的提高;聚丙烯纤维系列对基体混凝土抗渗性有很大提高;1∶1混杂纤维系列在小掺量时与聚丙烯纤维系列相差不大,但随掺量的增大,对基体的抗水渗透性能有降低作用;1∶2混杂纤维系列对基体的抗水渗透能力在掺量0.6%左右提高了21%;2∶1混杂纤维系列在掺量0.3%时,对基体混凝土的抗水渗透性能提高了25%.通过分析试验数据,阐述玄武岩纤维和聚丙烯纤维改善混凝土抗渗性能的机理,以及发生混杂效应的原因.

28 day-age experiment of water permeation resistance of basalt and polypropylene fiber reinforced concretes with fiber dosage of 0. 3%, 0. 6%, 0. 9% and 1.2%, and basalt-polypropylene hybrid fiber reinforced concrete with mixture ratio of 1 ： 1, 1 ： 2, 2 ： 1 was carried out with seepage height meth- od. The variation pattern of seepage of the series of fiber reinforced concretes was obtained. The result showed that the water permeation resistance of concretes with basalt fiber would be improved a little and that with polypropylene fiber would be greatly improved. The water permeation resistance of concretes with hybrid fiber of 1 ： 1 mixture ratio and small fiber dosage would be almost the same as that of polypro- pylene fiber concretes, but it would be decreased with the dosage increasing. The water permeation resistance of concretes with 1 ： 2 hybrid fiber would increase by 21% when fiber dosage was nearly 0. 6%; the water permeation resistance of concretes with 2 ： 1 mixture ratio would increase by 25% when fiber dosage was nearly 0. 3%. Through the data analysis of test results, the mechanism of water permeation resistance improvement of concrete with basalt and polypropylene fibers, and the origin of occurrence of hybrid effect was expounded.